Year US Dollars 1970 435673000 1971 520237000 1972 554353000 1973 631607000 1974 783760000 1975 817833000 1976 941718000 1977 1141625000 1978 1381696000 1979 1562191000 1980 1849034000 1981 2241835000 1982 2632034000 1983 2890238000 1984 2998355000 1985 3544639000 1986 4086689000 1987 4754432000 1988 5209641000 1989 5185722000 1990 5867505000 1991 6580744000 1992 6476091000 1993 6902623000 1994 7960616000 1995 8395502000 1996 8298763000 1997 8106315000 1998 9057341000 1999 9943047000 2000 9249851000 2001 8952127000 2002 10122937000 2003 10726003000 2004 11600417000 2005 11300132000 2006 11853451000 2007 14161317000 2008 16320825000 2009 19504197000 2010 21684211000 2011 25795383000 2012 35735941000 2013 39313859000 2014 42262753000 2015 43925209000 2016 46607902000